Cost-effective analysis of countermeasures for solar photovoltaic systems in distribution networks

The total installed photovoltaic (PV) system capacity of Japan is currently increasing rapidly. However, the reverse power flow from PV systems causes voltage rise in distribution networks. In this paper, we analyze the cost- effectiveness of various voltage rise countermeasures, including increasing conductor sizes, applying VAR compensators, and upgrading voltage levels. We categorize these countermeasures into two types, namely: Measure 1, in which the existing 6- kilovolt line is used, and Measure 2, in which a 22-kilovolt line is partially used. We compare the cost-effectiveness of Measure 1 and Measure 2 in a distribution feeder, and then in a distribution substation area. The results show that in a concentrated PV scenario, Measure 2 is more cost-effective than Measure 1. In addition, the PV hosting capacity is larger for Measure 2 than it is for Measure 1.